Vacuum cup and vacuum cup system



v4,e f of the work.

Along with 'these work can be handled rapidly.

vvacuumA tightly To the accomplishment of the foregoing and related ends,l theinvention, then, comprises the features hereinafterfully described, and particularly pointed out' in the claims, the following description setting yforth in detail certain illustrative. embodiments lof the invention, these being. 10'v indicative however of buiiai'ewy of the various ways in` which the principle:v of the invention maybelappliedr c Q We'arrive at, an eiIective-solution lof the problem by the employment of three cooperating ifea.-v` .These are: iirst, ,ajmodificationfofithe i `vacuum cup constructionso as tonreduce the" absolute minimum and si-l tures. g

entrapped air to the y y multaneously support thinsheetlmaterial against inward deflection by the vacuum;-` second, in-

corporating in the cup a contact operatedsp'ringiclosed air valve capable of keeping the source of shut of( except when the `.work has been brought against the cupjhwhereupo'n contact with a slight .up'iwiardi` projection of 'the valve stem depresses'it and opens-the valveap plying thefull vacuum to the cupipractieally instantaneously due to the minimum of entrapped air; and third, ran arrangement of parts facilitatfing'a quick release of the work"l Theeiects of these improvements are v(l) to y c w entirely eliminate leakage derived from uncovered'cupssince the latter are selectively "and Vautomi'ttically operable by contact with the l'work 'which maybe of any "size, and (2) to limit the work' oithey vacuum pump, to overcoming thel unavoidable L leakage around the elastic lips of those cups which are in actual operation. The needlessy workoif vfirst lieva'cuating a considerable amount of air enmain trappedin' the body'of the cups is reduced to a `l`negligible factor and there is no other source' of leakage except an unavoidable minimum which in some case, occurs around the c up lips. v third feature of providing for quick release of the The work adds 'greatly` to efficient use of the device.

"This last function is obtainedby thecinsertion fof a three-way valvejin the-main trunk line to the air pump kfor simultaneous Arelease of the vacuum in 'the'various cups 'which are active anda'cooperating adjustment of the relation of `the relative height of thevrubber liprof'the vacuum cup and the heightof" the "airvalve stem above 'the surface of the'main body of the cup which is common with thesurfa'ce of the table, if sevused lirl. a vcommon table. The

eral cupsv are l v t length of the air valve stem may beadjusted so thatit will project abovetho surface 4ortho body of each .cup atleast high Aenoughlto keep'the air valvefopen and maintainatmospheric pressurein'the cup, until the lip of the cup "has come free'from Athecontacted `surface This arrangement prevents retention of any residual. vacuum within the kbody-of the cup when the three-way 'valve isA opened to disconnect the pump and let outside air intov the system.` VAs soon as release takes place, the spring vacuum to be established invthisystem upon closing vof vthe three-way valve. '.This systeml eliminates much lost time iin changing work from one sheet to the next, r A' t t i 1 In the accompanying drawing; .t i y t `Figure 1` isa plan view of a fiat surfaced work table having embedded therein a series of vacuum cupsmade according to the present invention and showing themain andfbranchiines tothe sheaves desirous features we also provide a convenient means for quick release so that closes the air valve permitting a newl y cups and the three-way valve located in the mein line' I li'gure 2 is an enlarged section substantially on line'I-Z oi' Figure 1, the sectionl passing through the middle of .one of the vacuum cups l to show details of the construction;

Figurev 3 shows a section'of a table having a I. curved surfacewith vacuum lL'cups` embedded firmly held during a polishing operationrand; rv .111

Figurelf'showspinperspective view a .special Y Vacuumcupform for' holding formed panelsrfor i l l5 e,

radio cabinets; vacuum cups are'shown mounted intwo 'iiatlplaesfarrangm at a 90"- angle, fthe ltwoy planes beingoonnected bya curved corner having the samecurvature as the formed panels.

Referringlto Figure 1, theV vacuum mips arel` indicated as azwhole at III, and if are each positioned in a recess Il formed -in' thev surface of` a work supporting table, as illustrated in detail l in Figure'2. vEach cup assembly .includes a filler v e vping i2l occupying 'the maior portion roi v'the of thelcup. which plug hasy aprefe'rably integral stem yI3 ex'tendirigV throughfan Y .openingv itin the `bottom ofthe recess II.- `The plug andstem Vare provided with aooextensive contrai; openinggie;

and the wall of fthe opening in the plug portion Vis internally threaded as at le to Yttdii'iiitohly reg-u` ceive an .externally threaded valvemembei'. II`V whilothe stem is isextorhoily threaded as'et le 'tore'ceive a clamping nut Il. 21A washer 2l is `disposed in the recess il andhas an openingv il through which;v thestem not the plug rasees. .t

This',irasherv is provided with a recess ,2l of 'a contour; substantially conforming k to 1the contour of the lower surface-of theplug i2 for receiving the plug. Interposed between the adjacent,subi stantiallyy conical opposed walls 2l ofthe. plug', and washer is a molded rubber lipring Il. The.

parts are positioned as shown, and the nut Il is lv thereinand constructedlsoas to conform to the curvature of the table, sothat curved sheet ma-y terlal may be then threaded'on'thestemv so asto clamp the assembly together.

'rho lip-ring is molded' to o ring form toes to providea thin elastic projecting edgev adapted to seal of! leakage whenthere' is reduced pressure vwithin the cup;l In practise we preferto modify thoroonstruotiori'oi" the up ring `ooo'ordimrto the particular character of work which is to be done.

If the surface to beheld ris comparatively rough so that thereisdifilculty ln obtaining a tight .seal "against leakage, we prefer Ato shape the lip ring 'so thatthere is a" considerable projection ofthe rubbertlipcbeyond theedge of `ller Vplug Il,`and we also shape therubber ring so that the prof -jecting portionL is lrelatively' thin and ilexible.

This provides afmore effective seal for rough surfaces such` as plywood. If, .on `the other hand, the mainuse of thesyste'mis to be lin handling comparatively smoothsur'faces such as ysheet metal kor glass, Iwe then'V find that the foregoing feature isnecessaryand av narrow ring -having its edge projection likewise above the plane of the plug and of thefsurface of the table, butpf thicker` and `less flexiblerubber,y provides a satisfactory` seal and is Vsomewhat -more convenient and"durable'.

An importantfeature ofthe `invention is the design of the cup-withl reference to the filler-plug i2. ltiisessentialf that the Aplug I! occupy as large a proportion as possible .of the body of the cup as `this Wconstruction' reduces-objectionable entrapped alrfto the minimum. This also provides a support to yprevent the outside air'opres-t` to holding curved and even .irregularsurfacea It issalso notk restricted .to circular cups. l; For some purposes 'rectangular vcups `are kdesirable 'l since they may be.v spaced.. closer together solas vt0 increase' lthe vacuum-applying surface in a'l table of a given area. i Y Y Y It will now be evident that thefinventionfur- .nishesa` very inexpensive andeffective solution to the diiculties mentioned in the kforegoing del 'scriptiorn The inventionis of considerable'hassistance :in polishing plate glass. A vacuum table Y( nller plugs l2, is very exactly in the same plane p 'vasthe surface-of rthe table, provides a convenient carefullybuilt with an exceedingly true smooth bed containingaconsiderable number of vacuum `cups made .after the present inventionand accurateiy locatedfin the table sothat the surface of Aand,satisfactory true surfaced support yfor most L vofthe Work of; surfacing and polishing. At most,

it now only necessary to use the method of embedding the glassl in piasterof Parisfor the initial truingup ,ofA one side, and `as soon asa' reasonably true surfacel has been vestablished on e that side, the f glass Acanvbe transferred tothe vacuum ,bedy tableand the other side -trued up Vso `and polished ,on the table. When thatgis com` pleted, the sheet can bey turned over onthetable andthe 'first side brought-to a polish. "In many cases the glassis true enough `to vwork it ,on-,the vacuum table` from the start.

v A table ofl this character will an@ obviously hold either-magnetic ,or'non-rna'gnetic'zv sheet metal for grinding,and-polishing and :inthe case of magneticmetals, theformer d iiiiculty with `magv netic ytables inv removing-fthe polishingdust `is eliminated. Another advantage is thatfourisys- .tem avoids any great inrush of air through the airfvalvesof the individual cups such as would ltend to draw dust into the system and pump. f It .will also betseen Athat `a tableconstructedjafter the present invention is well adapted `for sanding plywood and the former diiilculties withlvleakage through uncovered openings whenworking with small panels on a large table donot occur. x Since the kcups may be spaced., inthe surface` of the tableas frequently as conditions require, the main diiiiculty of handling warped panels is also eliminated because the strong holding power of the high vacuum )in `the individual cups-first brought into action, isample to resist and tendency VVfor one portion, of a panel to spring upward vwhen another .portion is vpressed down against the table.- ,As festas any portion ofthe panel isv brought in contact with the table, it is immediately securely grippedL and `if there is a `warped portion, all that is necessary is to press that -portion down until the yentire panel vis contacted Vwith v the "tablewnen it is `hem securely in y aflatposition. l

In glass polishing theadv'antages of our method of quick release areimportant. The surface of glass is so" smooth thatl leakage atsthe lips o f the cups is practically nil so thata small ,residual vacuumin a multiplicity of cups would interfere seriously withremoval of the glass upon cornf pletion of thewo'rk, but by our combined feature of providing thethree-way valve and designing 7'0 the projecting portion ofthe airV valvey stems to alwaysproj'ect somewhat 'higher than'V the lips of the-cups,y Wemakeitimpossible for any vacuum to remain and interfere with ua vquick removal of thesheet from theY table 'as soon as tire-three,-

Way valve has been opened,-

'araches s i. Other modes'ofapplying the principlesof the An feature of tables and fvscuumnsystemslmade accordinrto the present invention;y which arises from our provisionxfor eliminating entrapped air-'from the system and of .eliminatingj alll leakage except around the edges v of the lip is; thev surprisingly `small airv ypump required tohan'dle a system having a large numbervofcups'. In actual practice, workingfrel-v Y atively smooth` materials where ,the lip-seal of theindividual cups is most eiiective, it hasbeen found inmanyjfcases that no mechanical pump is needed at ally and that an ordinary waterl tap aspirator connected .through Va' vacuum bottle to provided; withnumerous cups As .this verysimcostsseveral hundred dollars, the great economy `,the cups, is adequate'- to :handle a large table'' etlectedfby our lnew, typeof vacuum cup-and? vacuum cup system is apparent. This great gain is` obtained ,both by our method of eliminating jentrappedairand of avoiding leakage by providving means for keeping thesource of vacuum shut offfromall cups not in actual.operation.= iv

invention may be employed,ch'anges being made -asregardsthedetai1s described, provided the feaktures statedf in any'of the following claims, or

the vequivalentrof -such,be employed, f

- We A4claim:` t Y if 1f 1. v A vacuum cup systemfor holding surfaces of articles by suction, comprising a'work table .having a surface substantially conforming to the contour-of the. surface to v beheld, one or' more 1 ,vacuum cups embedded therein with their working `faces-parallelto the surface, each cup being` provided withan elastic marginal lip-ring slightly e projecting above *thesurfacet of i the table .1 and adapted to seal 10ft a vacuum produced betweenV av contacting surfa.ce,and .said cup,y a contactVl operated spring-closedr--airv valve having an' upwardV projecting Vvalve stem, said valve -being capable of-preventing lossof vacuum in the`v system but permitting suction when the cup is appliedto` a surface and the valve'stemf dejpressed, and means for producing a vacuum connected with said cup through said air. valve.

2. A vacuum cupvsystem as setforth in claim 1 `withfthe added feature that the amount ofvup-v ward projection of the `valve stem above the plane ofthe surface offthework table is greaterV than. the upward projection ofthe lip-ring of said 'cup above-said plane,` whereby to prevent closing; of

the valve untilgthe surface y,of the/article is out y of contact With'the lip-ring., s p

3, A'Avacuumfcup` system for holding: surfaces of v articles v.by suction vcomprising Va work table havingl a surface `V*substantially conforming to the contour of, the surfaces to be held, one or more vacuumcups embedded therein, each lcup being provided withan elastic rmarginal lip-ring supported by and projecting slightly above a central s filler plug having its'exposed surface in the form ofy an extensionrof `the vplane of the 'surface of the Ltable, a contact operated spring-closedfair valve having an upwardlyv projectingvalve stem mounted in; saidsfiller plug-,1said, valve beingv capable of preventing'loss -of vacuum inthe system but permitting suction when the cup is applied s toasurfaceand the valve stem depressed, land means lfor producing a vacuurnconnected with said cup through said airvalve. "l

. `4. vacuum cup` system as setsforth in claim `3 withsthe added feature thatthe amount of-upj ward projectionof the valve stem above the plane c: n iumcs c: tne'wcrs nuda cupsby suctionfrom an externalsource, the iin-` ciating with saidfplug a contact operated srn'inu` t closed air valve connecting tothe source of vac-` said valve being `capable of preventing loss of vacuum in the system `but permitting suction` contact with the lip-ating. l l

c t maar l the upwardproiection of the link-ring of raideur` abovesaicl` plane. wherebyto'preventl closing of l the valve until the surface ofthe article is out of `5. In a vacuum cup system for holding surfaces J of articles against one or more marginally sealed provement which comprises substantially` reduc--` ing the volume of airto be evacuated by nearly filling each cup with a filler plug adapted to support the surface which,` isbeing held and asse-` uuxnand having an upward proiectingvalve stem.

whenthe cupis applied valve stemjdepressed. l l v t p g gA vacuum cup for holdingv surfaces of articles to asurface the `by`suction,` comprising an elastic marginal lip#` ring and a contact operated spring-closed air valve `having `an upwardly `projecting valve "stem and` a connection for a sourceof vacuum.` said valve being capable of preventing leakage of air from the cup tothe source of vacuum, but per@` mitting suction when thefcup is applied Iitc `s.

i `surface and thefvalve stem depressed." i c `'L1A vacuum cup for holding surfaces of articles by suction, comprising an elastic marginal `11p-ring `supported byy and projecting, slightly" i ausm suction held, said means being H l l B e a central filles'` plus havinsftl esposedaurzmsummuauy comming to thermaux er the" surface to be held.a nd acontact operated spring-closed air valve mounted in said nJler plusY `having an upwardly projecting valve stem and a the valve vstem deprsed.

projection of the valve stem above the surface l of the nller` plug exceeds the normal upward pro` jection of the lip-ring above said surface, whereby to prevent closing cfpthe `valve until the surface p of the articleis out ci' contact with the lip-ring.

l `9. In'avacuum cup for holding surfaces of narticlas bysuction, the combination which` c0111-, i prises a marginal` seal capable `of retaining a vacuum :formed between said cup and a contacting surface and means for permitting vacuum to be applied to said cup from an external source "whensaid cup is in contact with a surface to be m alsceffective to prevent leakage of air into the source of vacuum "when `said cup is out of contact with the surface.

ALFRED I. FEATHERS'IUNE. JOHN EARL PLATI. ERICSSON H.` MERRITT. Y 

